"Yesterday night we saw an unprecedented, extraordinary and embarrassing political manipulation: they tried to hide the truth but won't be able to," Fernandez said in a message shared on Twitter.

Fernandez and her party Citizen Unity have demanded a recount.

The accusations come after Argentina's electoral authority decided to suspend vote counting as Fernandez narrowed in on her rival former Education Minister Esteban Bullrich.

With 95.58 percent of votes in Buenos Aires province counted — home to nearly 40 percent of Argentina's electorate — the ruling party led by Macri's candidate Bullrich had captured 34.19 percent while Fernandez was within a whisker with 34.11 percent.

At this point, the electoral authority stopped counting the votes without including 1,500 voting tables.

Though there has been no official declaration, Fernandez took the stage at a rally around 4:00 a.m. to claim victory as well as criticize the pace of the vote count.

"I never imagined I would have to ask for forgiveness from all Argentines for this embarrassment," she said. "It's an offense to democracy."

Since voting centers closed over 24 hours ago, the complete election results have not yet been released.